1. Field of the Invention.
This invention relates to the field of respiratory facial masks.
2. Discussion of the Background
Facial mask assemblies are widely used in respiratory care and therapy. Typically, the mask is sized to fit over the patient's nose (i.e., nasal mask) or nose and mouth (i.e., full face mask) and seal against the patient's face. The mask is commonly held in place by a harness arrangement that includes straps that extend about the back of the patient's head and are attached at multiple points (e.g., sides and top) to the mask itself. In use, a common problem often arises that the mask will tend to unseat and leak as the patient turns his or her head (e.g., from side-to-side) or rolls over in bed and the straps contact and are deflected by a pillow, blanket, or other object.
More specifically, as the patient for example moves his or her head from side-to-side, the skin and muscles of the head tend to move relative to the underlying skull bones. The end result is that the side straps pull with unequal forces on the mask (i.e., the side strap away from the direction of movement tends to draw tighter while the other side strap slackens). This can cause the mask to cock or rock off the patient's face creating a leak or gap between the mask and the side of the patient's face in the direction of movement. The same unequal forces and resulting leakage can be created if the patient rolls over and one of the straps contacts and is deflected laterally by a pillow, blanket, or other object. Various devices and modifications to mask structures have been developed to compensate for these undesirable effects; however, most of them are awkward and cumbersome and have not been widely accepted by patients and doctors.
With this in mind, the present invention was made. With it, a simple and effective way has been devised to compensate for the unequal forces that may develop on such facial masks and to prevent these unequal forces from unseating the mask and causing it to leak.